powershell - How to make LastWriteTime return culture sensitive date string -

i have this:

$logfileinfo = get-item c:\windows $logfileinfo.lastwritetime "explaining text: " + $logfileinfo.lastwritetime 

line 2 output is:

21. maj 2015 13:44:45 

line 3 output is:

explaining text: 05/21/2015 13:44:45 

it changes output, though same variable!?

how can line 2 output (naming month, , not reversing day/month), text in front, in line 3?

the default output system.datetime datetime:

"explaining text: " + $logfileinfo.lastwritetime.datetime